I. Field of the Invention
The present invention relates to a system and method for reliably and easily thawing frozen pipes in a safe and cost-effective manner, and more particularly to thawing branch line pipes such as those which feed kitchen and bathroom sinks.
II. Description of Prior Art
In many areas throughout the United States and other countries, the temperature in the wintertime, for example, gets so cold that water pipes that are near exterior walls tend to freeze up. Frozen pipes are not only an inconvenience, but if not attended to, could rupture leading to expensive and sometimes dangerous situations. Most often, the main water feed line into a dwelling or other structure is not the pipe that freezes up. Instead, the freeze usually occurs in a subsidiary or branch line pipe that is one of many branch lines feeding off the main line. These branch line pipes feed sinks, such as bathroom or kitchen sinks, which are often located adjacent an exterior wall, such that some length of the branch line pipe feeding that sink also runs near or is exposed to the cold of the exterior wall.
As will be appreciated, a typical sink includes cold and/or hot water lines which couple through respective turn-off valves to a faucet. Each branch line pipe usually has a portion that extends out of the floor or wall of the building and into a space below the sink, such as inside of a cabinet, such that the pipe portion is accessible under the sink without tearing into the floor or wall. That accessible portion of the branch line pipe couples directly to the inlet side of a turn-off valve which is also under the sink and inside the cabinet, for example. The outlet side of the turn-off valve couples to the faucet through a short feed tube under the sink to thereby provide water to the faucet. The accessible branch line pipe portion, turn-off valve and feed tube for each of the hot and/or cold water supplies thus define undersink plumbing components. The undersink plumbing components are under the sink, but outside the wall or floor from which the pipe portion projects, and are usually enclosed in the cabinet for ready access thereto. Unfortunately, the section of branch line pipes that tends to freeze is in the wall or ceiling (or below the floor) of the building upstream of the feed tube(s), turn-off valve(s), and accessible pipe portion(s) under the sink so as to not be readily accessible.
When there is a freeze in such a pipe section, the homeowner may be left with options that are not particularly desirable or safe. The homeowner could just "wait it out" and hope the pipe does not burst while waiting for the weather to warm up enough to thaw the pipe. This wait and see approach could be risky leaving the pipe vulnerable to rupture, not to mention the inconvenience of going without running water from that pipe for a possibly prolonged period of time. Another approach may be to attempt to indirectly thaw the frozen pipe section by applying heat to the adjacent floor, ceiling or wall, or to the accessible portion of the pipe under the sink, such as with a hair dryer or a torch. In these cases, either insufficient heat may be applied to actually cause the freeze to melt, or the danger of fire is greatly increased. A third alternative is to cut into the ceiling or wall of the house to expose the frozen section of the pipe to room air or to apply heat directly to the frozen section. Not only is this expensive and destructive, it leaves the homeowner exposed to a risk of fire.
Some systems have been proposed to alleviate frozen pipes, or to attempt to prevent their occurrence, such as shown in U.S. Pat. Nos. 4,986,311 to Mikkelson and 4,423,311 to Varney. In the Mikkelson patent, a hot water feed tube is coupled to the main water feed line and introduced into the water system of the house in an attempt to flush hot water from the upstream side of the water plumbing system to the downstream location of the freeze. The system of the Mikkelson patent is cumbersome and is believed to have many disadvantages. For example, water must be provided, yet the water lines may be frozen, and use of large quantities of hot water can be messy and undesirable. Moreover, the system may not work well to reach a freeze in a subsidiary or branch line pipe that is remote, and accessible only along a tortuous path, from the main water feed line, as is often the case with frozen branch line pipes.
The Varney patent proposes to add a permanent adaptor, apparently in the main water feed line and remotely upstream from the sinks, with a small heater inserted through the adaptor to heat the water as it travels downstream past the adaptor. The device of the Varney patent appears to be designed to be energized at all times during cold weather, with the hope of avoiding a freeze in the water line. The system of the Varney patent is also believed to have several drawbacks. For example, the system of the Varney patent appears to require power to the heater for extended periods of time, which could be costly and may unnecessarily warm the water, even in pipes that are to desirably carry cold water. Moreover, the permanent adaptor has a normally non-water carrying aperture for the heater element but which can present a source of leakage. Still further, as with the Mikkelson patent, the system of the Varney patent may be insufficient to reach and melt a freeze in pipe sections where freezes often occur, i.e., in the branch line pipes that feed sinks, as those sections are remote, and separated via a tortuous path, from the main water feed line.
The Mikkelson and Varney patent systems are thus not believed to be desirable or particularly useful in those typical situations of sink-feeding branch line pipe freezes. Hence, there is a need for a simple and reliable system and method by which to unfreeze frozen branch line pipes that feed sinks, such as kitchen or bathroom sinks.